ABS light on 1993 F-150 ext cab is on and off

I had the brakes replaced, the rotors, wheel bearings, caliper, pads. The brakes work fine. I can feel the ABS are working when I stopped on snow and ice this past winter. It's just the light goes on and off, seemingly at random. It's just annoying.

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I'm almost positive that you will find the inner bearing in the back of the brake rotor behind an oil seal. replace the oil seal when you do the bearing. Remove the brake caliper and the center axle nut and the rotor will literally fall off. Hope this helps.

I replaced the hub bearing assembly on drivers side twice and the light stayed on and the brakes worked fine. It was the wires (visible just above the tire on the frame) that rubbed against the frame that had shorted out. It was simply repaired and clip-stripped up out of the way. The light has been off every since then.

Normally a "pulsing" brake pedal means that that you have a warped brake rotor or the brake caliper is lose. I would start by taking the front wheel off and inspecting the brake pads and the rotor. If the brake pads are worn down bad replace them. Pay special attention to the brake rotors also as if the are grooved very bad, they should also be replaced.

Raise the vehicle and support on jack stands. Remove the wheels. Place the drip pan under the caliper. Loosen the 10 mm bleeder screw on the top of the caliper.

Step 2
Spread the brake pads apart with the common screwdriver. Place the screwdriver in the slot in the center of the caliper where the pads can be seen. With the nose of the screwdriver, pry between the rotor and the pad and pull the caliper outward toward you. The piston is being depressed into its housing as the caliper is pulled out. When the caliper comes to its limit outward, push the caliper back away from you and insert the screwdriver into the inside pad between the pad and the rotor. Once again pull the screwdriver toward you until the caliper piston is compressed into its bore.

Step 3
Tighten the 10 mm bleeder screw. Remove the caliper and support it where it is not hanging on the brake hose. Letting the caliper hang on the brake hose will damage the hose and cause brake failure.

Step 4
Remove the caliper support if it interferes with the removal of the rotor. Some vehicles don't require the removal of the support. Remove the rotor by pulling it off. If it is stuck, hit it with a hammer a few times between the studs.

Step 5
Install the caliper support and caliper in the reverse order they were taken off. Install the wheels and let the vehicle down. Check the brake fluid and fill as necessary to the proper level.

Step 6
Start the vehicle and pump the brakes very slowly until you have a high pedal. Remember that by expanding the calipers they have to re-adjust. You will not have any braking when you first start the car. Do not try to move the car until you have pumped the brake pedal sufficiently to feel a firm pedal.
Rear-Wheel-Drive Vehicles

Step 1
Raise the vehicle and support on jack stands. Remove the wheels. Place the drip pan under the caliper. Loosen the 10 mm bleeder screw on the top of the caliper.

Step 2
Spread the brake pads apart with the common screwdriver. Place the screwdriver in the slot in the center of the caliper where the pads can be seen. With the nose of the screwdriver, pry between the rotor and the pad and pull the caliper outward toward you. The piston is being depressed into its housing as the caliper is pulled out. When the caliper comes to its limit outward, push the caliper back away from you and insert the screwdriver into the inside pad between the pad and the rotor. Once again, pull the screwdriver toward you until the caliper piston is compressed into its bore.

Step 3
Tighten the 10 mm bleeder screw. Remove the caliper and support it where it is not hanging on the brake hose. Letting the caliper hang on the brake hose will damage the hose and cause brake failure.

Step 4
Remove the bearing cap in the center of the rotor. Remove the cotter pin. Remove the large nut that retains the bearings and rotor. Wobble the rotor with your hands and the front bearing will come out.

Step 5
Reinstall the spindle nut with just a few threads. Grabbing the rotor with both hands, pull the rotor off with slight down pressure and with a quick ****. The spindle nut will grab the rear bearing and seal as you pull the rotor off and come out at the same time.

Step 6
Install the bearings into the new rotor. Grease the bearings first and install the rear large bearing then install the grease seal with the hammer. Install the rotor on the spindle and insert the front small bearing followed by the large washer and the retaining nut.

Step 7
Tighten the retaining nut just until there is no longer any freeplay then tighten an additional 90 degrees. Do not over tighten the retaining nut as it will not allow the bearings to expand and they will wear out rapidly. Install the cotter pin.

Step 8
Install the caliper support and caliper in the reverse order they were taken off. Install the wheels and let the vehicle down. Check the brake fluid and fill as necessary to the proper level.

Step 9
Start the vehicle and pump the brakes very slowly until you have a high pedal. Remember that by expanding the calipers they have to re-adjust. You will not have any braking when you first start the car. Do not try to move the car until you have pumped the brake pedal sufficiently to feel a firm pedal

Is your ABS light on? If so, you have a bad wheel speed sensor at the LF wheel. Or, you may have rust buildup on the teeth that the speed sensor measures. Pull off the axle, and check the toothed gear that resided in the spindle.

If not, you may havea sticking caliper piston, or inadequate lubrication on the caliper slides.

u will need to check the wheel speed sensors behind the brake rotors to see if they got damaged or disconnected during the brake job, as long as the ABS light is on the Anti-lock brake system is disabled, regular braking without the need of ABS will feel fine.

Clean the control arm face and the bore before installing the hub and the bearing.

Installation Procedure

Notice: Refer to Fastener Notice in Service Precautions.

Install the brake shield and the hub and the bearing to the control arm with the four bolts. Be careful not to drop the hub and the bearing, as it could be damaged. Reconnect the ABS sensor. Tighten the hub and bearing bolts to 70 Nm (52 ft. lbs.).

have you check? the master cylinder. sometine when you get the rotors cut they dont come out right because they may be warped or to thin. if you did the job yourself you might have put the calipers in on the wrong side. this happens alot . if your rotors front and rear are fine then switch the calipers to the other side.